Field of the Invention
The present application relates generally to the field of molecular biology and genetics. Specifically, this application relates to methods and materials involved in modulating biomass productivity in microorganisms such as, for example, microalgae. This application further provides recombinant microorganisms such as microalgae having increased productivity.
Background of the Invention
Microalgae have recently attracted considerable interest owing to numerous consumer products and applications that can be produced from these organisms. The microalgae-based product portfolio stretches from biomass production for food and animal feed to valuable products extracted from microalgal biomass, including triglycerides which can be converted into biodiesel. With the development of advanced culture and screening techniques, microalgal biotechnology can help meet the high demands of food, pharmaceutical, and energy industries. Low biomass yields contribute to the relatively high cost of algal biofuels and other products. As a result, scientists are continually striving to improve algal biomass productivity.
Progression through the cell cycle in eukaryotes is regulated through synthesis/degradation and phosphorylation/dephosphorylation of cell cycle-regulating proteins. The Skp, Cullin, F-box containing complex (SCF complex) is a ubiquitin ligase complex that controls the transition between G1/S and G2/M phases by marking key proteins for proteasomal degradation (Cordozo and Pagano (2004) Nature Rev Mol Cell Biol 5:739-751; Vodermaier (2014) Curr Biol 14: R787-R796; Wei et al. (2004) Nature 428:194-198). In addition to ubiquitinating cell cycle proteins, the SCF complex marks various other cellular proteins for degradation. SCF complex contains three core subunits and a number of less critical components. The core components include SKP1, Cullin (CUL1), and F-box protein (SKP2, Cdc4). SKP1 serves as a bridging protein forming a connection between the Cullin and F-box proteins (Schulman et al. (2000) Nature 408:381-386).